The pill shrinks the part of the brain that controls your sex drive, according to new research.
Top scientists found that women taking the contraceptive pill have a significantly smaller hypothalamus – a brain region responsible for regulating hormones — which could be affecting the bedroom habits of over a million Australian women currently taking the oral contraception.
Damage to the hypothalamus can wreak havoc with a women's sex drive, mood, appetite, heart rate and sleep cycles.
The shocking revelation comes following a study, presented at the annual meeting of Radiological Society of North America, that examined 50 women – 21 of whom were using the pill, reports news.com.au.
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All 50 women underwent a brain scan, and doctors measured the size of the hypothalamus of each participant.
And doctors were stunned to discover the difference in brain structures in women taking the pill compared with those who weren't.
Impact on brain function
Dr Michael Lipton, professor of radiology at Albert Einstein College of Medicine in New York, said: "We found a dramatic difference in the size of the brain structures between women who were taking oral contraceptives and those who were not.
"This initial study shows a strong association and should motivate further investigation into the effects of oral contraceptives on brain structure and their potential impact on brain function."
Dr Lipton also found a strong correlation between smaller hypothalamic volume and greater anger and depressive symptoms.
Despite this, he said the finding was currently "preliminary".
Pill plays cupid
This is the first time structural effects of sex hormones, including oral contraceptive pills, on the human hypothalamus have been reported, according to the researchers.
It comes after it was revealed the pill can dictate who you fall in love with and significantly lower your sex drive.
Top psychologist Dr Sarah Hill revealed that it affected "sex, attraction, stress, hunger, eating patterns, emotion regulation, friendships, aggression, mood, learning, and so many other things".
She said women on the pill are attracted to less masculine men and are less interested in sex.
That's because the hormone progesterone, which sends a message to the body that ovulation is not required, is dominant throughout your cycle.
"Rather than experiencing an increased preference for sexy men at high fertility like naturally cycling women do, pill-taking women exhibit an unwavering preference for men with less masculine faces and voices," she said.
"This is the sort preferred by naturally cycling women during the second half of their cycles when progesterone is high."